1. Field of the Invention
The invention relates to a method for the disposal of asbestos or materials containing asbestos, wherein the asbestos or materials containing asbestos are transformed by grinding into a material which comprises non-fibrous, stable, mineral phases.
2. Description of the Related Art
As is known, fine-fibrous asbestos aggregates such as serpentine asbestos (chrysotile) and amphibole asbestos cause tissues to become diseased, and in particular lung cancer. The safe disposal of asbestos or materials containing asbestos is, therefore, of great importance. At present the disposal of asbestos or materials containing asbestos takes place by dumping. If need be, the waste material is solidified with cement before it is dumped. A great disadvantage of this type of disposal is that a later release of asbestos into the environment cannot be excluded.
It is known, it is true, to treat asbestos thermally and/or chemically with acids to destroy its health-endangering fiber structure, and if need be to influence it mechanically. However, the known methods used for this require a relatively large amount of energy, a considerable outlay on equipment and/or relatively long treatment times. In particular, treatment parameters such as time and temperature must be very accurately adjusted relative to one another. There also exists a particular treatment relationship for the various types of asbestos. When comminuting asbestos, a health-endangering dust occurs, and with some chemical reactions waste gases occur that must be collected. As a result thereof, known methods, which are specified in greater detail below, have not proved successful in practice and do not permit the desired large-scale industrial application in a satisfactory manner. According to Kirk-Othmer, Encyclopaedia of Chemical Technology, 1978, Wiley-Interscience, New York, US, 3rd edition, vol. 3, p. 272, chrysotile is first subjected at high temperatures to a thermal decomposition to ensure a dehydroxylation, and then to an intensive grinding. From DE-A-3 914 553 it is known to sinter the fibres of chrysotile and crocidolite at relatively high sintering temperatures whilst at the same time influencing them mechanically. Some methods propose to treat asbestos with acids to dissolve the fiber structure (WO-A-8 906 167; WO-A-8 810 234) and if need be to heat it at the same time to high temperatures (DE-A-3 728 787) or to influence it mechanically (JP-A-2 311 381). According to WO-A-9 100 123 it is provided that moistened asbestos should be treated with a water-soluble mineralising agent, e.g. in particular borate, to transform it into a non-asbestos containing product. To this end, the asbestos may, if necessary, be shredded before the coarsely comminuted asbestos fragments are exposed to the mineralising agent.